/*
  将下面异步代码使用 Promise 的方法改进
  尽量用看上去像同步代码的方式
  setTimeout(function () {
    var a = 'hello'
    setTimeout(function () {
      var b = 'lagou'
      setTimeout(function () {
        var c = 'I ♥ U'
        console.log(a + b +c)
      }, 10)
    }, 10)
  }, 10)
*/


let a = '';
let b = ''
let c = ''
let promise = new Promise(resolve => {
  resolve()
}, reject => {
  reject()
})

promise.then(() => {
  a = 'hello'
}).then(() => {
  b = 'lagou'
}).then(() => {
  c = 'I ♥ U'
  console.log(a + b + c)
})